Rotorcraft

ABSTRACT

An aircraft having a frame ( 1 ) and at least a rotor ( 2   a,    2   b ) for providing lift for the aircraft. The aircraft comprises elements for accommodation purposes. Furthermore, solar cells ( 5 ) are arranged on the aircraft for exploiting solar energy, and the rotor ( 2   a,    2   b ) comprises elements for adjusting the rotor ( 2   a,    2   b ) to exploit wind energy when the aircraft is substantially stationary.

CROSS REFERENCE TO RELATED APPLICATION

This is the 35 USC 371 national stage of international applicationPCT/FI98/00817 filed on Oct. 20, 1998, which designated the UnitedStates of America.

FIELD OF THE INVENTION

The invention relates to an aircraft having a frame and at least a rotorfor providing lift for the aircraft.

SUMMARY OF THE INVENTION

Publications FI-49949, DE-2 648 504, U.S. Pat. Nos. 2, 740, 595,4,123,018, WO-87/02004, U.S. Pat. Nos. 2,847,173 and 3,722,830 disclosevarious aircraft of a helicopter type. The aircraft disclosed in thepublications are not versatile enough and they consume plenty of fuel.

An object of the present invention is to provide an aircraft in whichthe above-described disadvantages can be avoided.

The aircraft of the invention is characterized in that it provides ameans for accommodation purposes, that solar cells are arranged on theaircraft for exploiting solar energy and that in connection with therotor, means are provided for exploiting wind energy by means of therotor.

It is an essential idea of the invention that the aircraft is adaptedfor moving and accommodation purposes and comprises a frame and at leasta rotor connected thereto for providing lift. Solar cells are arrangedon the frame and/or the rotor for exploiting solar energy and the rotoris so arranged that it enables the exploitation of wind energy. It is anidea of a preferred embodiment that the frame is convex.

It is an advantage of the invention that the aircraft, being adapted formoving and accommodation purposes, is extremely versatile. Solar energycan be exploited by means of the solar cells. When a rotor blade is soarranged that the device is also able to exploit wind energy, the amountof fuel used for flying and accommodation purposes can be considerablyreduced and, most preferably, no external fuel is required. Theefficiency and flying characteristics of the aircraft can be optimizedby making the frame convex.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in more detail in the accompanyingdrawings, in which

FIG. 1 is a schematic partial cross sectional side view of an aircraftof the invention,

FIG. 2 is a top view of the aircraft of FIG. 1,

FIG. 3 is a cross sectional side view of a part of the aircraft of FIG.1,

FIG. 4 is a schematic side view of a second aircraft of the invention,

FIG. 5 is a schematic front view of a third aircraft of the invention,and

FIG. 6 is a top view of the aircraft of FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows an aircraft comprising a frame 1 having on its outercircumference rotor rims 3 a and 3 b which are rotatable in oppositedirections and to which rotors 2 a and 2 b are connected. In thisapplication, the term rotor also refers to a rotating blade thatprovides lift.

The frame 1 also comprises windows 4 and solar cells 5 which are alsoarranged on the frame 1 for recovering solar energy. The bottom part ofthe frame 1 can be raised or lowered by lifting means 6. Alternatively,if the bottom part is fixedly fastened and the top part is detached, thetop part of the frame 1 can be raised or lowered by the same liftingmeans 6. Seats 7 can be moved forward and backward for adjusting thecentre of gravity of the apparatus. The backs of the seats 7 can bereclined into a horizontal position in the manner shown by a dashed linein FIG. 1, i.e. the aircraft provides a means for accommodationpurposes.

FIG. 2 is a top view of the aircraft. The rotors 2 a and 2 b rotate inopposite directions in the manner shown by arrows A and B. Some of thesolar cells 5 can also be arranged on the rotors 2 a and 2 b. The sizeof the apparatus can naturally vary according to the purpose of use andnumber of passengers. The frame 1 of a two-seater apparatus may be 3 min diameter, for example, and the rotor blades may be about 3 m inlength. Each rotor rim 3 a and 3 b may have 3 to 5 blades, for example.The solar cells 5 may then have a surface area of about 15 m², and theygenerate a power of about 1 kW. Batteries may weigh about 10 kg and theycan generate a power of about 2.5 kW for 2 minutes. The empty weight ofthe apparatus can then be about 100 to 150 kg. For increasing the powerit is advantageous to also place some of the solar cells 5 on the bottomsurfaces of the frame 1 and the rotors 2 a and 2 b, which makes itpossible to utilize radiation reflected from the clouds, for example,when the aircraft flies above the clouds.

FIG. 3 presents a rotating mechanism of the rotors 2 a and 2 b. Therotating mechanism comprises electric motors 8 which use rolls 9 tocounter rotate the rotor rims 3 a and 3 b and the rotors 2 a and 2 bconnected thereto. The electric motors 8 get their driving power frombatteries 11. Means 10 for adjusting the blade angle of the rotor arearranged in connection with the rotors 2 a and 2 b. The blade angle ofthe rotors can be adjusted by the means 10 so as to make the wind rotatethe rotors 2 a and 2 b when the aircraft is substantially stationary,for example. When permanent magnet motors, for example, are used as theelectric motors 8, they can be arranged to function as generators whichcharge the batteries 11 while the wind is rotating the rotors 2 a and 2b.

Take-off is preferably accomplished by setting the blade angles of therotors 2 a and 2 b to zero and speeding up the rotors 2 a and 2 b to aspeed about twice as high as the normal speed of rotation, after whichthe blade angle is increased, allowing the motion energy stored in therotors 2 a and 2 b and in the rotor rims 3 a and 3 b to be used fortake-off. The energy stored in the batteries 11 can also be used duringtake-off. Naturally, solar energy collected by the solar cells 5 canalso be exploited in every situation. The aircraft can also useturbulence of the airflow for providing lift. In that case, the anglesof the slowly rotating rotor blades are adjusted according to thedirections of the airflow so as to provide the maximum lift. Wind energycan also be recovered from turbulence while the aircraft is moving bysuitably adjusting the blades of the rotors 2 a and 2 b. The bladeangles are optimized by independent adjustment controllers which adjusteach blade individually. The aircraft is controlled by adjusting thetorque of the rotors 2 a and 2 b with respect to the frame 1, enablingthe frame 1 to be turned in the desired direction. The speed of motionis controlled by adjusting the centre of gravity and the blade angles ofthe rotors 2 a and 2 b.

The frame 1 is preferably convex, i.e. the surface area of the upperpart is larger than that of the bottom part. This provides very goodefficiency and flying and gliding characteristics. Likewise, the longand slowly rotating rotors 2 a and 2 b improve these characteristics andprovide a good flying stability by the gyroscopic force generated by therotors 2 a and 2 b. The conical structure presented in FIG. 4 isparticularly advantageous for gliding and flying characteristics. In thesolution of FIG. 4, the rotors 2 a and 2 b are positioned one on theother above the frame 1, thereby providing a simple aircraft structure.

FIG. 5 is a front view of a third aircraft of the invention, and FIG. 6is a top view of a corresponding aircraft. In this solution, the rotors2 a and 2 b are positioned substantially side by side. In that case, theaircraft can be controlled and manoeuvred in a very versatile manner.When the aircraft flies in the direction of arrow C, the rotors 2 a and2 b rotate in opposite directions in accordance with arrows A and B inthe manner presented in FIG. 6.

The drawings and the related description are only intended to illustratethe idea of the invention. The details of the invention may vary withinthe scope of the claims. Naturally, electric energy generated from thesun and the wind by the aircraft can also be used for activitiesassociated with accommodation in the aircraft, or electricity can besupplied to an electrical network. A fuel cell can also be used as asource of energy. The aircraft can also be so constructed that it isable to float, which enables it to land and move on water. Wind energycan also be easily recovered and exploited while the aircraft isfloating on water.

What is claimed is:
 1. An aircraft comprising: a conical asymmetricalframe, said frame having a maximum cross-sectional chord defining anupper part and a bottom part, a surface area of said upper part beinglarger than a surface area of said bottom part; at least one rotorconnected to said frame for providing lift for said aircraft; apassenger cabin within said frame, said passenger cabin having means foraccommodation purposes; solar cells mounted on said aircraft forexploiting solar energy; and wind energy exploitation controllersconnected to said at least one rotor.
 2. The aircraft as claimed inclaim 1 wherein at least one of said solar cells is attached to saidframe.
 3. The aircraft as claimed in claim 2 wherein at least one ofsaid solar cells is attached to said bottom part of said frame.
 4. Theaircraft as claimed in claim 1 wherein at least one of said solar cellsis attached to said at least one rotor.
 5. The aircraft as claimed inclaim 1 wherein said at least one rotor is located above said frame. 6.The aircraft as claimed in claim 1 further comprising: a rotating rotorrim on an outer circumference of said frame, said rotor being attachedto said rotating rotor rim.
 7. The aircraft as claimed in claim 1further comprising: at least two rotors, wherein said at least tworotors are configured to rotate in opposite directions.
 8. The aircraftas claimed in claim 7 wherein said at least two rotors are configuredside by side.
 9. The aircraft as claimed in claim 1 further comprising:batteries arranged within said frame for storing solar energy and windenergy.